The proposed research is a comparison of resource intensity per visit between adult primary care delivered in a teaching hospital outpatient department (OPD) and in a community health center (CHC). Resource intensity per visit is measured in four ways: (1) total provider minutes, (2) provider minutes converted to dollars by weighting time by relative salaries, (3) the dollar value of diagnostic precedures ordered or performed calculated from California Relative Value Units, and (4) total resource use, which is the dollar value of provider time plus diagnostic procedures. These measures of resource intensity will be compared across sites of care for a number of specified medical conditions, ranging from the clinically uncomplicated to the complex. In addition, both medical and psychosocical casemix will be compared across sites. Hypotheses are as follows: Resource intensity per visit will be greater in the hospital OPD relative to the CHC; the greater availability of sophisticated laboratory and other diagnostic equipment as well as the presence of residents are presumed to account for this. Medical casemix is hypothesized not to differ between the two sites while psychosocial casemix is expected to be more severe in the OPD. The data are comprised of 2,331 visits to 7 CHCs and 1,674 visits to 3 OPDs located in the city of Boston. They were collected as part of the Ambulatory Care Project at the Heller School of Brandeis University in the summers of 1982 and 1983. The survey instrument is similar is its elements to the questionnaire used by Robert Mendenhall at the University of Southern California, which in turn is derived from the National Medical Care Survey (NAMCS). Multivariate analysis, including multiple regression analysis, residual analysis and analysis of variance will be applied to the data to test the hypotheses. The policy relevance of the proposed research is that reimbursement for primary care delivered in the hospital OPD is several times that received for care provided in the CHC; thus knowledge of which factors contribute to the greater resource costs in the hospital OPD is a critical issue. If the above hypotheses are confirmed, there are significant implications for prospective payment mechanisms for ambulatory care.